Moore, J.A.

One-Third of Reef-Building Corals Face Elevated Extinction Risk from Climate Change and Local Impacts

The conservation status of 845 zooxanthellate reef-building coral species was assessed by using International Union for Conservation of Nature Red List Criteria. Of the 704 species that could be assigned conservation status, 32.8% are in categories with elevated risk of extinction. Declines in abundance are associated with bleaching and diseases driven by elevated sea surface temperatures, with extinction risk further exacerbated by local-scale anthropogenic disturbances. The proportion of corals threatened with extinction has increased dramatically in recent decades and exceeds that of most terrestrial groups. The Caribbean has the largest proportion of corals in high extinction risk categories, whereas the Coral Triangle (western Pacific) has the highest proportion of species in all categories of elevated extinction risk. Our results emphasize the widespread plight of coral reefs and the urgent need to enact conservation measures. 

Date
2008
Data type
Scientific article
Theme
Research and monitoring
Journal

Endolymphatic Sac Use and Reproductive Activity in the Lesser Antilles Endemic Gecko Gonatodes antillensis (Gekkota: Sphaerodactylidae)

Geckos are among the most diverse radiations of lizards; however, the lack of baseline natural history data on the reproductive biology for many species creates a challenge for predicting their long-term persistence. This study aims to fill a gap in our understanding of the reproductive biology of an enigmatic nocturnal gecko endemic to the islands of Curaçao and Bonaire: Gonatodes antillensis. Using radiographs of specimens from natural history collections, we conduct the first investigation of the potential role of endolymphatic sacs in the reproduction of the species. We find that females have larger endolymphatic sacs than males, with further quantification of endolymphatic sac sizes between females with or without visible eggs supporting the hypothesis that calcium stores are built up in the early reproductive phase and depleted during the development of the egg. Additionally, we combined data on endolymphatic sacs sizes with examinations of gravidity to expand the known reproductive interval of the species into fall and winter months and suggest the possibility of year-round reproduction. Along with providing baseline data, our findings raise a new conservation concern for the species. The spread of the invasive gecko Hemidactylus mabouia has resulted in a notable decline in the abundance of Gonatodes antillensis across its native range. This decline has been attributed to Hemidactylus mabouia acting as both a competitor and possible predator of Gonatodes antillensis. However, stress can inhibit calcium uptake in endolymphatic sacs, and these findings raise the possibility that Hemidactylus mabouia may also be indirectly affecting the reproductive success of this species.

Date
2017
Data type
Scientific article
Theme
Research and monitoring
Geographic location
Bonaire
Curacao